This case has been reviewed and confirmed to be working as designed. The user is creating a Global Texture (_GrabPassTransparent) from a custom pass and utilizing it through another custom pass via DrawRenderers. For cases involving MSAA, the texture is flagged to resolve when a subsequent pass uses it.

In this specific project, when an overlay camera is used, no pass is marked to utilize the global texture. As a result, the user is using the global texture without notifying the Render Graph (RG) about this dependency. Consequently, RG is unaware of the resource dependency and may even merge the pass generating the texture with the pass that uses or samples the global texture. This gives RG no opportunity to properly resolve the texture. Conversely, when no overlay camera is present, the URP "Draw UIToolkit/uGUI Overlay" pass is automatically marked to UseAllGlobals, which triggers a read operation. This causes the texture to resolve, making it available for the user’s custom pass.

Recommended Solution:

To address this issue, the user should explicitly notify the Render Graph of the global texture dependency by including the following line in their DrawRenderers pass (TransparentObjectsRenderPass_DrawRenderers):

builder.UseGlobalTexture(Shader.PropertyToID(_settings.GlobalTextureID));

Below is the corrected code snippet for reference:

using (var builder = renderGraph.AddRasterRenderPass<PassData>($"{_name}_DrawRenderers", out var passData, _profilingSampler))
{
passData.RendererList = rendererList;

builder.AllowPassCulling(false);

builder.UseRendererList(passData.RendererList);

builder.SetRenderAttachment(source, 0);
builder.SetRenderAttachmentDepth(resourceData.activeDepthTexture);
builder.UseGlobalTexture(Shader.PropertyToID(_settings.GlobalTextureID));

builder.SetRenderFunc((PassData data, RasterGraphContext context) => ExecuteRenderListPass(data, context));
}